Separation of platelets from other blood cells in continuous-flow by dielectrophoresis field-flow-fractionation

We present a microfluidic device capable of separating platelets from other blood cells in continuous flow using dielectrophoresis field-flow-fractionation. The use of hydrodynamic focusing in combination with the application of a dielectrophoretic force allows the separation of platelets from red blood cells due to their size difference. The theoretical cell trajectory has been calculated by numerical simulations of the electrical field and flow speed, and is in agreement with the experimental results. The proposed device uses the so-called "liquid electrodes" design and can be used with low applied voltages, as low as 10 V(pp). The obtained separation is very efficient, the device being able to achieve a very high purity of platelets of 98.8% with less than 2% cell loss. Its low-voltage operation makes it particularly suitable for point-of-care applications. It could further be used for the separation of other cell types based on their size difference, as well as in combination with other sorting techniques to separate multiple cell populations from each other.     

Inter-disciplinarity in sport sciences: The neuroscience example*

Abstract

Sport science is a relatively recent domain of research born from the interactions of different disciplines related to sport. According to the European College of sport science (http://sport-science.org): “scientific excellence in sport science is based on disciplinary competence embedded in the understanding that its essence lies in its multi- and interdisciplinary character”. In this respect, the scientific domain of neuroscience has been developed within such a framework. Influenced by the apparent homogeneity of this scientific domain, the present paper reviews three important research topics in sport from a neuroscientific perspective. These topics concern the relationship between mind and motor action, the effects of cognition on motor performance, and the study of certain mental states (such as the “flow” effect, see below) and motor control issues to understand, for example, the neural substrates of the vertical squat jump. Based on the few extensive examples shown in this review, we argue that by adopting an interdisciplinary paradigm, sport science can emulate neuroscience in becoming a mono-discipline.     

Reliability of unipodal and bipodal counter movement jump landings in a recreational male population

Movement patterns during landing have been suggested to be related to injury risk. The purpose of this study was to determine the inter-session reliability of kinematic variables and ground reaction forces during landing in a population of male recreational athletes after a counter movement jump. Both unipodal and bipodal landings were evaluated. Furthermore, the possibility to improve landing reliability with a verbal instruction was also studied. Twenty-four male volunteers with no history of lower extremity trauma were randomly assigned to two groups (with and without verbal landing instruction). An optoelectronic 3D system and force plates were used to measure the lower limb joint angles and the ground reaction forces during landing. Intraclass correlation values show moderate to excellent inter-session reliability for the bipodal task (ICC average: 0.80, range: 0.46–0.97) and poor to excellent reliability for the unipodal task (ICC average: >0.75, range: 0.20–0.95). However, large standard errors of measurement values at the ankle joint at impact (27.6?±?11.5°) and for the vertical ground reaction forces (394?±?1091 N) show that some variables may not be usable in practice. The verbal instruction had a negative effect on the reliability of unipodal landing but improved the reliability of bipodal landing. These findings show that the reliability of a landing task is influenced by its motor complexity as well as the instruction given to the subject.     

An integrative review of in-class activities that enable active learning in college science classroom settings

ABSTRACT

Engaging students in active learning is linked to positive learning outcomes. This study aims to synthesise the peer-reviewed literature about ‘active learning’ in college science classroom settings. Using the methodology of an integrative literature review, 337 articles archived in the Educational Resources Information Center (ERIC) are examined. Four categories of in-class activities emerge: (i) individual non-polling activities, (ii) in-class polling activities, (iii) whole-class discussion or activities, and (iv) in-class group activities. Examining the collection of identified in-class activities through the lens of a theoretical framework informed by constructivism and social interdependence theory, we synthesise the reviewed literature to propose the active learning strategies (ALSs) model and the instructional decisions to enable active learning (IDEAL) theory. The ALS model characterises in-class activities in terms of the degrees to which they are designed to promote (i) peer interaction and (ii) social interdependence. The IDEAL theory includes the ALS model and provides a framework for conceptualising different levels of the general concept ‘active learning’ and how these levels connect to instructional decision-making about using in-class activities. The proposed ALS model and IDEAL theory can be utilised to inform instructional decision-making and future research about active learning in college science courses.     

Universities’ Autonomy in Times of Changing Higher Education Governance: A study of the Swiss academic labour market

Although eternally debated, the issue of autonomy in higher education is rarely analysed in its complexity. To address this issue, this article uses an analytical matrix which combines the distinction between substantive and procedural autonomy and the distinction between HEI governing bodies, academic professions and individual academics. This framework allows for analysing—by the example of the Swiss academic labour market—how changes in national steering can lead to the redistribution of autonomy between the mentioned actors. Further insights relate to the observed higher education system’s decentralised character. Empirical findings—based on the examination of three special programmes initiated by the federal government—indicate that HEI actors lose some substantive autonomy in favour of the Confederation, and—against the general tendency induced by New Public Management to reinforce HEI governing bodies—procedural autonomy is rather redistributed to individual academics and academic professions.     

The harmful aspect of teacher conditional support on students’ self-perception of school competence

When children perceive a conditional support, they only feel loved and encouraged for their ability to meet others’ standards. This may lead them to develop high sensitivity to errors and anxiety and low perception of competence. In this study, we examined the relationship between the perceived conditional support from teacher and children’s self-perception of school competence. We tested the mediating effect of sensitivity to errors and test anxiety in the relationship between teacher conditional support and children’s perception of school competence. Participants were 524 elementary school students (aged 9–10 years). The results showed that the greater the extent to which the children perceived conditional support from their teacher, the lower their self-perceived scholastic competence. They also confirm that this relationship was mediated by sensitivity to errors and test anxiety.     

Etude en temps réel de la production eEcrite chez des enfants de sept et huit ans

The aim of this research is to study on-line written production in children. Twelve seven year old children and twelve eight year old children were asked to compose two texts (a narrative and a report). They were filmed as they wrote in order to investigate the temporal caracteristics of their composition (pauses, rates…). The results show three main findings:

- the rates increases from seven to eight year old.

- pauses times varied according to the syntactic organisation of the next sentence.

- longer pause times are localized after punctuation marks and before connective.

     

The illusion of scholastic incompetence and peer acceptance in primary school

This paper reports results from two studies aimed at examining whether perception of social acceptance and actual social acceptance differ according to the presence of an illusion of scholastic incompetence. Results of both studies conducted in Belgium and in Quebec (respectively 179 and 543 participants) show that children’s illusion of scholastic incompetence is linked to a negative perception of social acceptance. However, according to the evaluation by peers, social acceptance of those children is similar to the others. This suggests a generalization of the negative bias of self-evaluation to both academic and social domains. The discussion proposes further variables that could improve the understanding of the origin of the illusion of incompetence.     

Physical health of today's school children

The health habits of today's children will largely determine their subsequent health as adults of the twenty-first century. Smoking, inactivity, poor dietary practices, drug and alcohol abuse, and other deleterious habits may develop early, yet exert lifelong influences. This paper contains a review of (a) statistics and research on major health status indicators in school-aged children, (b) behaviors that contribute to disease risk, and (c) school-based interventions designed to change risk behaviors and enhance wellness. Activities that can be initiated by classroom teachers are emphasized in the concluding section of the paper. Through early intervention, enhanced longevity and quality of life may be accomplished.